水平井分段压裂测试获取地层参数

Multi-Stage Fracturing and Test in Horizontal Well to Acquire Formation Parameter

压裂施工方案的设计需要真实的地层参数来指导。以往通常采用测井解释、室内岩心实验、数值模拟等方法认识储层参数,但其受仪器精度、样品选取等诸多外界因素的影响。小型压裂测试获得地层参数方法已经广泛应用于油气田压裂增产中,但其测试时间短,关井期间很难出现拟线性流乃至拟径向流,不能准确反映非常规油气藏储层性质。页岩、致密砂岩、煤层等储层通常需要水平井分段压裂才能获得经济产能,但对于非均质较强储层,水平井每段往往具有不同的破裂特征,因此在对一段压裂设计前需要获得该段准确的地层参数。Q2水平井分段压裂测试时,使用电缆输送带压力仪器的桥塞封隔测试段,注液测试,然后下桥塞封堵下一段,再注液测试,再封堵,从而实现在水平井中分段、一次性测试获取地层参数的目的。

Fracturing operation design need real formation parameters to guide,while,in the past,these reservoir parameters are gained by well logging interpretation,lab core analysis and numerical simulation method,but the results are usually affected by precision of instrument,sample selection and many other external factors. Mini-frac testing has been widely used in oil and gas field,but its testing time is too short and linear flow and radial flow may not appear in such short time,so these methods mentioned above are not suitable for unconventional oil and gas reservoirs. For reservoirs of shale,tight gas sand and coal seam,economical producing of that requires the creation of multiple transverse fractures in a long horizontal well,but each segment has different cracking character,so it's necessary to get the accurate formation parameters. In well Q2,bridge plug with pressure apparatus was conveyed by cable to seal the measuring section,and then carried out the next section testing,repeated the exercise and completed the entire test in the horizontal well-bore.